Improvement in furnaces for roasting ores



P. J. MITCHELL.

Furnaces fo r Roasting 0res.,

NOJBLQO O, I PatentedJune9,1874.

WITNESSES: INVE TUB: WW XW I BY UNITED STATES PATENT OFFICE.

PENTEOOST J. MITCHELL, OF SALT LAKE CITY, UTAH TERRITORY, ASSIGNOR TOHIMSELF AND JOSEPH E. GAY, OF NEV YORK CITY.

IMPROVEMENT IN FURNACES FOR ROASTING ORES.

Specification forming part of Letters Patent No. 151,900, dated June 9,1874; application filed May 16, 1874.

To all whom it may concern:

Beitknown that I,PENTECOST J. Mr'rorrnLL, of Salt Lake City, in thecounty of Salt Lake and Territory of Utah, have invented a new andimproved oven for desulphurizing or call oining ores of iron, copper,silver, lead, and other ores or minerals carrying or containing ironpyrites, sulphur, arsenic, and other deleterious substances, of whichthe following is a specification Figure 1 is a plan view of theapparatus embodying my invention. Fig. 2 is a horizontal section of thesame. Fig. 3 is a longitudinal section, and Fig. 4 is a transversesection.

Similar letters of reference indicate corresponding parts.

Iconstruct an oven of rectangular structure, of brick or otherfire-proof material, of which N N are the side walls, and arrangethereon hoppers A, of cast or wrought iron, with a movable side, a, tobe opened or closed by means of a shaft, 1, and chain Q. The ores ormaterials for calcination are placed within the hoppers, where theyremain a few hours, when they are dropped through the action of thesliding doors upon the calcining-floor F F, which is constructed ofcast-iron plates supported upon brick lines R B, through which the heatis conducted from the furnaces O O, and returned over the working-floorthrough the flue 0, re oeivin g an additional supply of heat from thefurnaces D D. The smoke and impure gases are carried oil by the draft ofthe chimney K K K through the lines J J and the condensers L L,consisting of a showering or sprinkling apparatus, through which wateris let fall, by which a portion of the escaping sulphur, arsenic, &c.,are deposited in the pans M M and removed at pleasure. The ores orminerals in process of calcination are manipulated by workmen usinghooks or rabbles for that purpose through the doors B B and I I. When itis sufiiciently prepared it is precipitated through the opening G intocooling-arch H H, from which it is transported to reduction-works. Theletters E indicate the ash-pits to the furnaces (J O and D D.

The object of my invention is toexpel, by means of heat, sulphur,arsenic, and other deleterious substances usually found in nature,associated and combined with ores of iron, silver, copper, lead, andother ores or minerals, by reason of which they are comparativelyvalueless until removed.

Having thus described my invention, I claim as new and desire to secureby Letters Patent A desulphurizing-oven comprising the adjustablehoppers A, floor F, flues R, O, and J, furnaces U l), and condensingapparatus L M, combined and arranged substantially as specified.

PENTECOST J. MITCHELL.

lVitnesses:

J. O. CAMERON, J12,

. WM. PAUL, Sr.

